WASHINGTON — On this snow-draped Inauguration Day in Washington, a few people on Capitol Hill were thinking about the worst: a catastrophic attack that could kill or incapacitate most members of Congress, the president, the vice president and the cabinet.

The unseen presence at this first inauguration since Sept. 11, 2001, is al-Qaida, whose terrorists showed three years ago how capable they were of killing thousands of Americans in one place at one time.

At 9:30 on inauguration morning, in his office in the Longworth Building, a short walk from where the president would soon take his oath, Rep. Brad Sherman, D-Calif., said, “It is very clear that al-Qaida wishes to do only things that are destabilizing to the United States. More modest terrorists would have blown up an apartment building in the last three years. But al-Qaida is not dead and they don’t think small. They think in terms of the power of the United States and how do you symbolically destroy, physically destroy, that power.”

Changing the line of succession
Last year, Sherman introduced a bill that would change the line of presidential succession, removing the Speaker of the House and the President Pro Tempore of the Senate, whom federal law places second and third in line.

Under Sherman’s bill, the line of succession would begin with the Secretary of State and extend through the Cabinet, but would for the first time include officials outside Washington, D.C., and in some cases outside the borders of the United States, specifically the ambassador to the United Nations, the ambassador to Great Britain and a few other American ambassadors.

Sherman said the danger to continuity if al-Qaida attacked on Inauguration Day would be especially acute if one party’s presidential candidate won the White House without his cabinet appointees being confirmed by Jan. 20 and the outgoing president was of the opposing party.

“Imagine if John Kerry had been elected and (Attorney General) John Ashcroft were still serving” and was the sole survivor in the line of succession, he said.

“A nation that elects Kerry as president should not get Ashcroft as president. Likewise, imagine that we Democrats had won the House and President Bush had won the presidency. A nation that elects George Bush shouldn’t get Nancy Pelosi as president.”

The concern about an Inauguration Day attack crosses party lines.

Three branches in one place
On Wednesday, as the clocked ticked toward Bush’s swearing-in, one of his fellow Texans, Republican Sen. John Cornyn, told MSNBC.com in an interview in his office, “Tomorrow will be one of our most vulnerable times. The judicial, executive and legislative branches of government will all be collected in one relatively small place and you don’t need to use too much imagination to think about the risks of an improvised explosive device, a ‘dirty’ bomb, a nuclear device, or a biological or chemical war.”

While Cornyn acknowledged the security preparations that the Secret Service, the Capitol Police and other agencies made to protect the inauguration, “there is some risk the government could be decapitated, creating a lot of potential for chaos. And really what it means, if this unthinkable occurrence happened, is martial law, until such time as government could re-constitute itself.”

The Succession Act of 1947 sets the line of successors to the presidency, starting with the House Speaker, Senate President Pro Tempore, then the Secretary of State and stretching through the rest of the Cabinet.

There will be one Cabinet member who will not attend Bush’s swearing in.

If Bush, Vice President Cheney and all others in the line of succession were killed in a terrorist attack, that Cabinet member would become the president.

Last year, Cornyn introduced a bill which, similar to Sherman’s, would remove the Speaker and the President Pro Tempore from the line of succession.

Other legal scholars have suggested ways to ensure that a terrorist assault on the nation’s capitol could not succeed in decapitating the government. One idea: empowering the president to name a few state governors as potential successors.

A more intractable problem than presidential succession is the terrorist act that kills most or all members of the House of Representatives.

According to Article I of the Constitution, House vacancies can be filled only by special election, unlike the Senate where governors fill vacancies by appointment.

In the aftermath of a catastrophic attack, the House might be unable to muster a quorum to do business. Under the current interpretation of the quorum requirement, only a majority of members chosen, sworn and living is needed for a quorum.

But if an attack left only 20 House members living, then 11 members, at least for a time, could pass laws governing the nation.

Early this month, the House approved a Republican proposal to permit the Speaker to lower the quorum requirement in the wake of an attack.

Long-term incapacity
More worrisome, according to a May 2003 report by the Continuity of Government Commission, which includes such Washington veterans as former House speakers Tom Foley and Newt Gingrich, is the possibility that a chemical or biological attack could incapacitate, rather than kill, most House members or senators.

As the report noted, “neither the House nor the Senate can fill vacancies due to temporary incapacitation. For incapacitated members, the relevant seats would be effectively vacant until the member recovers, resigns, or dies and is replaced, or until the next general election.”

The report warned, “Mass incapacitation makes it virtually certain that Congress would be unable to reach its quorum requirement even under its most lenient interpretation.”

Last year Rep. Brian Baird, D-Wash., offered a bill that would require each member of the House, before taking his oath of office, to present his state’s governor with a list of at least two stand-ins to temporarily replace him if he were killed or incapacitated. The House rejected Baird’s measure by a vote of 353-63.

Both Cornyn and Sherman offered "sense of the Congress" resolutions last year that recommended that a president whose term is coming to an end and who will not succeed himself submit his successor’s Cabinet nominations for Senate confirmation.

The line of succession for the new president would then be safely in place before he took his oath of office on Jan. 20.

"There hasn’t been the political will to address these issues," Cornyn said Wednesday. “There was some reluctance to address some of this before the election lest there be some implicit message sent that we expected a change in the president."

“We as the typing and chattering class, the press, the politicians, and the people who look at the MSNBC web site, have not done our job” to ensure continuity of government, Sherman said Wednesday. We Americans “leave ourselves vulnerable just because we’re too busy at partisan sniping to carry out the non-partisan or bipartisan functions,” he added.

But Sherman said the House had made some progress last year by holding Judiciary subcommittee hearings on continuity and he expects the committee to write legislation in this session of Congress.

Cornyn has urged his successor as chairman of the Senate Judiciary subcommittee on the Constitution, Sen. Sam Brownback of Kansas, to take up the continuity issue in the new Congress.

That way, by the time the next president takes his or her oath on Inauguration Day 2009, the nation would at least have an insurance policy against a decapitation attack.